There is one issue you should clarify with the MP rep before you try and start the changes. If you are just upgrading the tix from Biz to First on the same flight, you just add the additional points to cover the difference, no problem. Find out if you change the itinerary; point of origin; will they have to cancel, redeposit the points and re-book. Redepositing usually is immediate but they state it can take longer. While you are waiting for the redeposit to happen (if it's not immediate and sometimes even if it is) the tix you are trying to get could go to someone else and the biz seats you just cancelled could also be gone too. I know most people don't have enough miles, but the best way is to use miles to purchase the first class seats, then cancel and redeposit on the biz tix. I currently have 3 Emirates biz awards, 3 first seats came up (called and verified), purchased a few miles to make up the difference, MP rep was on the line waiting, asked her to do the upgrade. In those 2 minutes the seats had been purchased by some one else. BTW, Emirates First is amazing!